Heat-exchange apparatus



Marh 31, 1931. A. E. LEEK 1,798,330

HEAT EXCHANGE APPARATUS Filed May 6, 1-926 2 Sheets-Sheet 1 C 0 f% a\00000000000 m venan March 31, 1931.

Filed May 6, 1926 I I I A. E. LEEK HEAT EXCHANGE APPARATUS 2Sheets-Sheet 2 'aaz,

mveniar' Patented Mar. 31, 1931 UNITED STATES Application filed May 6.1926, Seri PATENT. OFFICE ALBERT EDWARD LEEK, WIGAN, ENGLANDHEAT-EXCHANGE APPARATUS This invention relates to heat exchangeapparatus and has for its object to provide an improved construction andarrangement of the economizer or heater as employed for 5 water heatingpurposes, to adapt it also for the efiicient pre-heating of air,required, for

example, for combustion in the generator furnace or furnaces.

The inventlon comprises a combmed air and wate r heater for steamgenerating plant consisting of the combination of nested tubes or ductsand an enclosing casing or enclosing tubes such that intermediate ductsare provided through which the hot gases flow, the

latter contacting with the exterior surface of the inner units and theinterior surface of the outer units of said nested tubes or ducts.

Referring to the accompanying explanatory drawings:-

Figure l is a sectional elevation showing,

in diagrammatic form one manner of carrylng the invention into effect.

Figure 2 IS a sectional end view showing one arrangement of the tubes orducts of my improved economizer or feed water heater and Figure 3 asimilar View showing another arrangement.

Figure 4; is a sectional View in diagrammatic form showing anothermanner of carrying the invention into effect.

The same reference letters in the different views indicate the same orsimilar parts.

As is illustrated at Figures 1 and 2, the

water tubes (in (of which in Figure 1) extending only four are shownbetween headers as b of the economizer or feed water heater, are eachprovlded with an outer tube 0 extending between the end plates hot gased of a casing e. The ous products admitted at f flow through the spacesbetween the said nested tubes at and a, passing and returning throughthose in half to the outlet at g. gases is indicated by the arrows 1 atFigure 1.

The air to casing c which is fitted sion plat through from f through thehalf of the casing e the upper Such flow of the hot said spaces in thelower be heated is admitted at h to the with a baflie or divie i suchthat the air after passing the spaces between the respective al No.107,230, and in Great Britain September 18, 1925.

outer tubes 0 in the upper half of the casing, returns through the likespaces in the lower half to the outlet at Such flow of the air, which isin a counter direction to the flow of the hot gases, is indicated by thearrows 2 at Figure 1.

The water flows through one set of tubes a and returns through the otherset. It may be passed through one set of tubes only or through more thantwo sets to suit require deflect the air from row of water tubes a isenclosed by one outer H tube or duct 0 of a rectangular section. As inthe previous example, the hot gases flow through the spaces between theexterior of the water tubes and the interior of the enclosing tubes orducts 0, whilst the air flows in the spaces, as 1, between the exteriorsurfaces of the said ducts c. The latter may be corrugated and the tubesplaced in a staggered formation.

In the arrangement shown in Figure 4, the air is passed through tubes m,encloses concentric hot gas and water tubes 0 and a respectively. Theseparate tubesmay be connected to headers as shown. Or the arrangementmay be such as to cause the air and water to be heated in severalstages: a

single stage heating as shown may however be utilized.

Suitably curved deflecting surfaces are provided for the respectivechanges of direction of the gases and of the air with a view to themaintenance of the velocity of flow.

The surfaces of the tubes exposed to the hot gaseous products ofcombustion can be cleaned by the aid, for example, of steam ]ets in theknown manner.

each of which What I claim is A combined air, Water and flue-gas heatinterchanger comprising in combination a circular easing, end platesspaced from the ends of said casing, pairs of tubes arrangedconcentrically one Within the other between said end plates and arrangedin quincunX, means for passing flue gas through the annular passagebetween said tubes which are arranged so that the gas flows in doublepass, means for passing Water through the inner tubes and means forpassing air over the outer surfaces of said tubes such that the air andWater flow in double pass and in contra flow to the movement of the fluegas from Which heatis extracted, and fiat, longitudinal, segmentalplates arranged Within said casing, each plate being parallel in crosssectional View to a line through the axes of the nearest row of tubes,so as to restrict the passage of air through the apparatus and to avoiddead spaces.

In testimony whereof I name to this specification.

ALBERT EDYVARD LEEK.

have signed my

